1. Field of the Invention
The present invention relates to farm implements and, more particularly, to an air conveying apparatus for replenishing particulate material such as seed, fertilizer, herbicide or insecticide in one or more tanks of an air seeder or other farm implement.
2. Description of the Related Art
Agricultural material dispensing equipment frequently employs a material tank either supported on the dispensing device or on a supply cart drawn across a field in conjunction with the dispensing device. Such arrangements are encountered on fertilizer spreaders, planters, air seeders, etc. Periodic replenishment of the material supply in the tank is required.
One typical replenishing technique employs a screw auger or belt conveyor which feeds the material from a source such as a supply vehicle to the tank. Grain augers, conveyor belts and similar mechanical seed handling equipment may cause damage to certain types of seeds.
Such damage is significantly reduced by employing an air conveying system, for example, as shown in U.S. patent application Ser. No. 14/301,717 filed Jun. 11, 2014, where an air flow, either from an air cart fan or from a dedicated pneumatic source, is supplied to a material reservoir, such as a seed hopper, where that air flow passes through one or more restrictions to create a region of increased air velocity and reduced air pressure and a so-called venturi effect. The venturi effect essentially creates a suction to minimize the contact friction of particles against the bottom portions of transfer hoses and for ingesting as many particles as possible of agricultural material from the hopper providing an air entrained flow of material. This air flow and material particles are conveyed to the tank where the material is deposited and excess air vented. The air conveying systems significantly reduce seed damage, however, the potential for damage to seeds and other fragile agricultural products remains. Moreover, the products tend to accumulate more in some tank areas than others resulting in a non-uniform product distribution and corresponding non-uniformity of product delivery to the metering system. Multiple outlet locations within the tank ameliorate this problem, however certain drawbacks and problems remain
The seeds exit the tubes at high velocity (in order to minimize the filling time of the tank by the operator). The main problem is that the seeds are either hitting the tank walls at high velocity (bouncing violently, which could damage the seeds) or being carried throughout the tank by random vortices. The random vortices disrupt the even filling of the tank. Finally, if the operator wishes to add only a few small bags to the tank, the random filling would mean that some seed meters are not covered properly (or would starve prematurely). This would cause errors during seeding since product could not be distributed evenly.
What is needed in the art is an air conveying system which does not throw seeds abruptly against the tank walls nor create vortices inside the tank, and distributes seeds evenly in the tank.